Discloses poppy plants (Papaver bracteatum) that produces seed capsules and an extractable quantity of thebaine in the first growing season after germination, wherein the plant is produced from seed deposited with the National Collections of Industrial and Marine Bacteria Limited under accession number NCIMB 41534 or NCIMB 41535. Further discloses mutant or derivative plants, seed or reproductive material derived from the disclosed plant strains. The thebaine compound is an opioid alkaloid useful in manufacture of certain analgesic pharmaceuticals.